New research by Alcatel-Lucent's Bell Labs division has reached a new optical network transmission record: 100 petabits per second.kilometer.

The bit-per-second.kilometers unit of measure is a combination of speed and distance and is considered by Alcatel-Lucent to be a standard measure for high-speed optical transmission.

The researchers used 155 lasers to transmit the data at rate of 100 gigabits per second. The total of 100 petabits per second.kilometer was calculated by multiplying the 155 lasers by the 100-gigabit speed (15.5 Terabit per second) over the entire 7,000 kilometer distance used in the study. In practical terms, that's the distance between Paris and Chicago.

As a result, the Alcatel-Lucent test's speed maxed out at the equivalent of 100 million gigabits per second.kilometer.

"The previous result achieved by Bell Labs earlier this year was slightly over half the result announced in this release and made use of half as many lasers," an spokesperson for Alcatel-Lucent (NYSE: ALU) told InternetNews.com.

Researchers faced a number of obstacles before hitting the milestone.

"The challenge was harnessing a diverse array of technologies in modulation, transmission, and signal processing and making innovative use of coherent detection techniques," the spokesperson said.

Bell Labs' researchers were able to achieve the 100 petabits-per-second.kilometer milestone with an optical network with repeaters placed every 90 kilometers. The repeater is an optical technology that maintains signal strength. The 90-kilometer distance between repeaters was 20 percent further apart than what is normally used in filed deployments.

In order to get the better performance, Bell Labs researchers used a technology called coherent detection, which provides enhanced optical capabilities. According to Alcatel-Lucent, coherent detection enabled the researchers to increase capacity by increasing the number of light sources introduced into a single fiber.

The 100 petabits-per-second.kilometer research is not specific to Ethernet as a protocol, however.

"The experiment was conducted agnostic to any given protocol," the Alcatel-Lucent spokesperson explained. "However, dimensioning in the experiment was done to emulate Ethernet, taking into account the protocol overhead."

While the 100 petabits-per-second.kilometer mark is a doubling of Bell Labs' previous record, even higher optical transmission figures could come in the future.

"We expect that results beyond this will be possible," the Alcatel-Lucent spokesperson said.